The present invention relates to eyeglasses of the kind defined in the preamble of claim 1.
Thus, the invention relates to eyeglasses that function to make contours stand out more clearly and distinctly to the wearer and to enable the wearer to discern light-coloured objects more easily, in a range of vision that is dominated predominantly by green coloured vegetation, said eyeglasses having a light transmission that varies with the wavelength of said light.
The inventive eyeglasses are particularly intended to enable a golfer to discern the contour curvature and slope of grass-covered ground sharply and clearly, and also to enable a golf ball lying in grass, rough vegetation and other places to be discovered more easily.
It is well known, for instance from U.S. Pat. No. 5,157,426, that certain informatory details in an environment dominated by green vegetation can be identified more easily when wearing eyeglasses that have significantly reduced light transmission over essentially the whole of the sequence band discerned by the human eye, with the exception of the infrared range (wavelengths longer than 700 nm) and to a limited extent in the blue/green and blue/violet ranges (500-520 nm and shorter than 435 nm respectively).
DE-A1-31 13 833 teaches eyeglass lenses having light transmission in a narow range near the infrared limit only.
DE-A1-35 34 575 teaches eyeglass lenses for colour contrast amplification with reduced transmission in respect of wavelengths above 720 nm and in respective wavelengths that lie between 550 and 600 nm.
Although these known devices provide some advantages with respect to facilitating identification of certain elements in a green environment, none of said devices provides a fully satisfactory solution to the difficulties experienced by golfers in particular when they shall strike a golf ball or identify a golf course contour.
Accordingly, an object of the invention is to provide eyeglasses that will enable, for instance, a golfer to identify contours and light-coloured objects such as a golf ball more easily in a range of vision or field of view that is dominated by green vegetation.
This object is achieved with eyeglasses constructed in accordance with the accompanying claim 1.
Further embodiments of the invention are set forth in the accompanying dependent claim.
Fundamentally, the invention can be considered to lie in the lens having a special frequency-dependent transmission, and in the lens also including a horizontal polarisation filter. A particularly favourable embodiment of the invention can be achieved by combining a commercially available colour compensation filter, Kodak Wratten filter, Magenta CC 40 M, with a commercially available horizontal polarisation filter, Polaroid HN 32. A common feature of these filters is that they both have a transmission curve according to claim 1, with t=xe2x88x9220% -units and curve deviations of 20% -units from the straight line T at 450 and 550 nm respectively.
According to a further development of the invention, two such Kodak Wratten filters can be combined with a Polaroid HN 32 filter.